Those who have GreaseMonkey installed on your system, I’ve already covered the script that auto replays youtube videos and auto replays youtube playlists.
Not many of you will have GreaseMonkey script installed on your system and this is for you people. There is a new Firefox Add-On, that adds infinite replay loop functionality to YouTube videos.
This is still an experimentail add-on. You can install this as in with no conditions what so ever.
The infinite loop feature is not available for playlists yet.
[ Download YouTube Auto Replay Add-On ]
Related Post: Did you know that you can change youtube video position / order in Playlist.